Study protocol

Study protocol articles will only be considered for proposed or ongoing trials that have not completed patient recruitment at the time of submission. Please confirm the status of your study at submission.

If the study has already undergone full external peer review as part of the ethics approval or funding process, the study protocol will usually only undergo editorial peer review by the handling editor. Proof of both ethics and funding will be required, and we recommend that authors provide the relevant documentation on submission. Study protocols without major external funding will undergo full, external peer review. Study protocols without ethical approval will generally not be considered.

Protocols of randomized trials should follow the SPIRIT guidelines, including the SPIRIT flow diagram in the main body of the text, with the populated checklist provided as an additional file. All protocols must have a trial registration number included as the last line of the abstract, as described in our editorial policies.

The information below details the section headings that you should include in your manuscript and what information should be within each section.

Please note that your manuscript must include a 'Declarations' section including all of the subheadings (please see below for more information).

Title page

The title page should:

• present a title that includes, if appropriate, the study design e.g.:
  • "A versus B in the treatment of C: a randomized controlled trial", "X is a risk factor for Y: a case control study", "What is the impact of factor X on subject Y: A systematic review"
  • or for non-clinical or non-research studies: a description of what the article reports
• list the full names and institutional addresses for all authors
  • if a collaboration group should be listed as an author, please list the Group name as an author. If you would like the names of the individual members of the Group to be searchable through their individual PubMed records, please include this information in the “Acknowledgements” section in accordance with the instructions below
  • Large Language Models (LLMs), such as ChatGPT, do not currently satisfy our authorship criteria. Notably an attribution of authorship carries with it accountability for the work, which cannot be effectively applied to LLMs. Use of an LLM should be properly documented in the Methods section (and if a Methods section is not available, in a suitable alternative part) of the manuscript
• indicate the corresponding author

Abstract

The Abstract should not exceed 350 words. Please minimize the use of abbreviations and do not cite references in the abstract. The abstract must include the following separate sections:

• Background: the context and purpose of the study
• Methods: how the study will be performed
• Discussion: a brief summary and potential implications
• Trial registration: If your article reports the results of a health care intervention on human participants, it must be registered in an appropriate registry and the registration number and date of registration should be in stated in this section. If it was not registered prospectively (before enrollment of the first participant), you should include the words 'retrospectively registered'. See our editorial policies for more information on trial registration

Keywords

Three to ten keywords representing the main content of the article.

Background

The Background section should explain the background to the study, its aims, a summary of the existing literature and why this study is necessary or its contribution to the field.

Methods/Design

The methods section should include:

• the aim, design and setting of the study
• the characteristics of participants or description of materials
• a clear description of all processes, interventions and comparisons. Generic drug names should generally be used. When proprietary brands are used in research, include the brand names in parentheses
• the type of statistical analysis used, including a power calculation if appropriate.

Discussion

This should include a discussion of any practical or operational issues involved in performing the study and any issues not covered in other sections.

List of abbreviations

If abbreviations are used in the text they should be defined in the text at first use, and a list of abbreviations should be provided.